Integrated circuit (IC) packages are used for protection and mounting of semiconductor dies onto printed circuit boards. Electrical contacts or “pads” of semiconductor dies can be electrically connected to the leads of the IC package by several mechanisms including wire bonding and controlled collapse chip connection (“C4” or “flip chip”). Complex, high pad count semiconductor dies such as application-specific integrated circuits and microprocessors may necessitate the use of multi-layer IC packages in order to route the many signal, power, and ground connections to and from the semiconductor die and the pins or contacts of the IC package. The layers of the IC package may include layers having different thicknesses, such as thicker “core layers” in the center sandwiched by thinner “buildup layers.” The buildup layers and core layers can include alternating layers of conductor and dielectric. The conductor layers may include conductive traces for conveying signals, or substantially solid or continuous conductor planes for conveying higher currents for power and ground. Electrical connections between conductor layers are made with vias or micro vias, which are vertical holes through a substrate layer that include a conductor such as tin, gold, or copper. In some applications it may be beneficial to include one or more voltage regulators within the IC package for the purpose of supplying power to the semiconductor die load.